Synthetic Turf Seaming with Adhesive Mesh Components

ABSTRACT

Novel adhesive scrim and application methods using polyurethane and polyurea adhesives are provided for joining segments of artificial turf.

The present application is a continuation-in-part of U.S. ApplicationSer. No. 15/338,294 filed Oct. 28, 2016 which in turn claims priority toU.S. Provisional Patent Application No. 62/247,676 filed Oct. 28, 2015and U.S. Provisional Patent Application No. 62/262,801 filed Dec. 3,2015.

FIELD OF THE INVENTION

Artificial turf is in widespread use on sports playing fields. Manyartificial turf fields are laid in strips that are seamed together.Strips of artificial turf may be seamed together in numerous waysincluding applying adhesives, sewing the edges together, or utilizingvarious fastener systems. The present invention relates to an improvedseaming method, adhesive mesh and system.

BACKGROUND OF THE INVENTION

Artificial turf surfaces are well known as replacements for naturalgrass surfaces in stadiums, playgrounds, and many other facilities andapplications. The artificial surfaces stand up to wear better thannatural grass, require minimal maintenance, and can be used in shadedareas where natural grass is difficult to grow.

Artificial turf is usually manufactured of tufts of extrudedpolypropylene, polyethylene, or polyamide ribbons that have been placedin a backing sheet comprising one or more layers, and most typicallywoven polyester. The tufted backing sheet is then typically coated witha secondary backing such as a heat set resin, commonly polyurethane foroutdoor installations, for securing the tufts in place in the backingmaterial. Artificial turf is manufactured in strips of about 12 to 15feet in width and delivered to installation sites in rolls. Theartificial turf is often laid over a resilient cushioning layer. Joiningroll sections of synthetic turf may require sewing or gluing the edgestogether. In many cases, the artificial turf is infilled with a granularmixture of rubber and sand or other suitable materials in order to keepthe grass ribbons upright and to provide a more natural playing surface.

Artificial turf is manufactured in strips of about 12 to 15 feet inwidth and delivered to installation sites in rolls. In U.S. Pat. No.5,958,527, joining roll sections of synthetic turf required sewing orgluing the edges together. U.S. Pat. Nos. 4,581,269 and 7,838,096disclosed fastening rolled sections of artificial turf using flexibleplastic staples or reinforcing fasteners. In U.S. Pat. Nos. 4,822,658,5,382,462; and 6,083,596, various hooked carpet tapes are utilized and adetailed hook and loop fastening system is described in Publication2002/0136846. Publication U.S. 2010/0068423 discloses a single componentmoisture cure polyurethane adhesive. U.S. Publications 2004/0234719 and2012/0186729 disclose the use of hot melt adhesives for joining stripsof artificial turf.

While traditionally sections of artificial turf were sewn together atthe seams, sewing has three significant disadvantages. First, sewing islabor intensive and requires experienced installers to implementproperly. Secondly, some backing fabrics, especially multi-layer wovenand FLW (fiber lock weave) backings, may be so thick or rigid as to beimpractical to sew. Finally, thread for sewing a seam effects amechanical fastening that concentrates stress at fastening points whileleaving unbonded spaces between each stitch. This causes the stressbetween turf sections to be concentrated at stitch locations rather thandistributing stress evenly over a large bonding area as can be achievedwith gluing.

Artificial turf is often secured in place by laying down the strips oftufted fabric on the resilient cushion or other subsurface that can besprayed with glue to help stabilize the turf, and a total glue down willgenerally produce the best installation. Even in a total glue downinstallation, it is important to seam the sections of artificial turf toprevent edges from working loose over time. When the strips ofartificial turf are laid down separately, the seams must be secured andthis is typically accomplished by the use of glue in one of severalfashions. For instance, substrates may be laid down that underlie theseams of the artificial turf and a layer of glue can be spread acrossthe substrates and then the edges of two adjacent pieces of artificialturf laid down upon the layer of glue. This process is labor intensiveand requires workers to spread glue with tools such as trowels.Furthermore, timing issues for both the creation of adequate “greenstrength” and final cured strength often result in the necessity ofallowing seams to cure overnight while weighted to ensure there is nomovement of the turf strips.

Green strength or “grab” is a measurement of the adhesive propertyholding two surfaces together when first contacted while the adhesive isstill “green” and before it develops its ultimate bonding propertieswhen fully cured. A high green strength adhesive helps overcome surfacemovement such as expansion, contraction, wind lift, edge curl, creep,wrinkling, and buoyancy resulting from temperature, humidity, rain,wind, and other weather conditions during installation. It also helpsovercome shape memory from stiffness during cold weather installations.Of course, the adhesive should also have strong bonding properties whenfully cured and the adhesive should stick to the subsurface for anapplicable installation, whether that be asphalt, concrete, wood, shockabsorbent underlayments, or strips of seaming tape as well as to thebacking of the artificial turf surface being installed.

The use of hot melt adhesives results in a faster final bonding of theseams since there is no cure time. In this case, two strips ofartificial turf are laid edge to edge on a support surface over a basetape having a lower surface resting on the support surface or resilientcushion and an upper surface of the base tape will carry a layer of hotmelt adhesive. Then preferably a wheeled device is rolled down the seam,lifting the adjacent edges of turf, heating the hot melt adhesive, andthen returning the edges of the strips of artificial turf to the hotadhesive where the edges are firmly bonded.

Hot melt adhesive reaches its final bonding strength relatively quickly,however, particularly on sunny days, the hot melt may be relatively slowto establish adequate grab and thus the installation can be slower andmore labor intensive than when utilizing a curing adhesive with goodgreen strength. On hot and sunny days, some thermoplastic hot melts mayresoften. Finally, because thermoplastic hot melt is applied in arelatively thick form that becomes very hard in cold weather, the seams,numbers, and other inserts bonded with hot melt adhesives may havehigher Gmax and hardness underfoot than other parts of the same field.

An alternative method of securing seams is needed that providesrelatively rapid bonding times, sufficient softness not to pose injuryor playability issues, and operable over a wide range of humidity andtemperature conditions. To this end, the present invention is directedto the application of two part polyurethane adhesive on a substrate andthe use of a mobile spray rig that promotes deposition of a mixed twopart polyurethane adhesive along substrates positioned at seam linesfrom a hose with spray attachment.

Furthermore, many artificial turf playing surfaces include features thatare added for decorative or functional reasons such as numbers, letters,logos, yard lines, and side line or end zone markings. While it ispossible to manufacture synthetic turf where the associated features areformed directly as the synthetic fibers are tufted in the manufacturingprocess, the more typical process for installing these visual featureshas been accomplished using an inlay process. This process involvescutting various segments of different color artificial turf material forassembly. Assembly is then accomplished by laying the cut pieces facedown, using hot melt to preliminarily attach adjacent pieces, andfinally securing pieces with the use of a polyurethane coated substratethat is rolled, covered and allowed to cure for up to about twenty-fourhours.

As described in more detail below, the process of assembling the inlaysis time consuming and requires considerable work space and labor. Inaddition, once the inlay has been completed and installed on site, thehot melt used for the initial attachment of adjacent pieces has provento be incompatible with polyurethane adhesives. Specifically, thepolyurethane continues to outgas or sublimate over time and causes areaction that degrades the hot melt. This leaves a gap between adjacentsegments of the inlay which can be further weakened both by theincreased likelihood of a snag from athlete or other user of theartificial turf surface and by moisture entering the seam between theadjacent inlay segments. The result is that inlays on artificial turffields may begin to fail after six or seven years rather than the ten totwelve year warranty periods that are typical for such installations.Therefore, it is desirable to produce a new technique for assemblinginlays in a more efficient fashion and techniques for ensuring a morelasting joinder between adjacent inlay segments.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described in detail below withreference to the following drawing figures in which the use of likenumerals in different figures is intended to illustrate like components.

FIG. 1 is a cross-sectional view at a seam between two strips ofartificial turf according to one embodiment;

FIG. 2 is a top plan view of a polyurethane spray system suitable foruse in practicing the invention; and

FIG. 3 is a cross-sectional view at a seam between two strips ofartificial turf during the application of the polyurethane system to asubstrate upon which the strips of artificial turf will be bonded.

FIG. 4 is an illustration of an exemplary system for polyurethaneadhesive application;

FIG. 5 is a top plan view of a sports field depicting possible inlaylocations;

FIG. 6A through 6C depict prior art inlays on artificial turf fields;

FIG. 7 is a perspective view of a water jet cutting system;

FIG. 8 is a perspective view of a water jet cutting apparatus withartificial turf laid face down, backing side up, on the cutting surface;

FIG. 9 is a perspective view of the artificial turf of FIG. 8 after ithas been cut and with segments removed;

FIG. 10 is a work space covered with plastic sheeting;

FIG. 11 is the work space of FIG. 10 with the initial inlay segmentspositioned on the plastic sheeting;

FIG. 12 is the work surface of FIG. 10 with the majority of the inlaysegments positioned;

FIG. 13 is the work surface of FIG. 10 with all the inlay segmentspositioned and at the beginning of the process of utilizing hot melt tojoin segments together;

FIG. 14 is a close-up view of the use of a hot melt gun to apply a hotmelt bead to join segments together;

FIG. 15 shows an inlay at the completion of the hot melt joining stageof assembly;

FIG. 16 illustrates the inlay of FIG. 15 as polyurethane adhesive coatedsubstrate strips are applied to the seams;

FIG. 17 illustrates the use of a doctor blade to apply polyurethaneadhesive to strips of substrate;

FIG. 18A illustrates the application of a polyurethane adhesive coatedsubstrate strip over a hot melt seam;

FIG. 18B illustrates the use of spray dispensed “blue glue” over hotmelt seams;

FIG. 19 illustrates the inlay as the application of polyurethane coatedstrips is nearly complete;

FIG. 20 is a perspective view of the inlay after application ofpolyurethane coated adhesive strips and as the inlay is being coveredwith a plastic sheet and being rolled;

FIG. 21 is a perspective view illustrating the placement of plywoodboards over the plastic sheeting to weight the inlay as it cures;

FIG. 22 is a perspective view illustrating the inlay after the boardsand plastic sheet have been removed and as the inlay is being turnedface side up;

FIG. 23 is a perspective view of the face side of the nearly completedinlay;

FIG. 24 is a close-up view of finishing work along the seams of thecompleted inlay;

FIG. 25A is a sectional view of a prior art inlay seam with hot meltadhesive;

FIG. 25B is a sectional view of a prior art inlay seam with degraded hotmelt adhesive;

FIG. 26A is a perspective view of mesh scrim with pressure sensitiveadhesive according to embodiments of the present invention;

FIG. 26B is a plan view of mesh scrim with pressure sensitive adhesiveaccording to embodiments of the present invention with a center adhesiveand marker;

FIG. 27 is a perspective view of inlay segments with scrim placed tohold the segments in alignment;

FIG. 28 is a sectional view of the joinder of adjacent inlay segmentsutilizing mesh scrim, pressure sensitive adhesive, and polyurethane; and

FIG. 29 is a logic flow chart of exemplary steps in practicing an aspectof the invention.

DETAILED DESCRIPTION

Referring now to the drawings for a better understanding of theinvention, FIG. 1 is a cross-sectional view between the seam of twostrips of artificial turf, 10, 11. Artificial turf strips 10, 11 eachinclude upstanding filament material 12 resembling or simulating bladesof grass extending upwards from a woven backing 14. It will beunderstood that many artificial surfaces will also include a particulateinfill among the upstanding rows of fibers after installation. After thefilament material 12 has been tufted in the backing 14, secondarybacking 16 is applied. This backing may be a single layer of resin suchas urethane or latex, or it may also include a cushion layer. Generally,for an outdoor installation, it is important that the strips ofartificial turf be sufficiently porous that appropriate drainage willoccur without excessive puddling or accumulation of water that mightdamage the installation or render the surface unplayable.

The first artificial turf strip 10 has a first edge 20 and the secondartificial turf strip 11 has a second edge 21 and the edges 20,21 are tobe seamed in close proximity to one another, generally with less than1/16^(th) of an inch separation. In order to accomplish this seaming,the surface 18 on which the artificial turf is installed, frequently aresilient polymeric material, will have a substrate 32 placed upon it atthe approximate location of the seam. The substrate is optionallyadhered to the base material 18 by appropriate adhesive layer 34.Adhesive layer 34 may be a contact adhesive and the substrate providedwith release tape for ease of installation or other adhesive systems maybe used. The substrate 32 provides a consistent surface for the depositof the seaming adhesive 30. While some base materials might allow fordirect application of the seaming adhesive, other base materials thatcould include dirt, sand, asphalt, and concrete, may benefit from theuse of the substrate to support the adhesive.

Upon the substrate 32 is deposited a seaming adhesive, such as a layerof polyurethane material 30 that is preferably a two part curingpolyurethane system such as DuraPur® UL-4500 manufactured by IFSIndustries. A desirable two component polyurethane adhesive will provideexcellent water resistance, hydrolytic stability, and appropriateworking times for complex constructions, typically on the order oftwenty to sixty minutes. In addition, the polyurethane adhesive shouldmaintain a hardness rating of less than about 70 durometer in order toavoid creating harder spots on the artificial turf surface where seamsor numerals are installed, and also to prevent increasing the G-maxrating of the field. Preferable two part adhesives have relatively highsolids content and viscosity. Viscosity is preferably above about 25,000cps for both the polyol and isocyanate components and the mixture.

It can be seen that the substrate 32 is wider than the layer ofpolyurethane material 30 so that it forms a barrier between thepolyurethane adhesive and the mounting surface 18. The width of thepolyurethane adhesive should be about 1.5 to 4 inches on either side ofthe center line of the seam so as to provide a well distributed adhesiveforce. Application of an adhesive layer having overall width of aboutfour to six inches and a thickness of about 10 to 300 mils is generallypreferred. The inclusion of moisture in the catalyst or polyol resultsin some foaming as the polyurethane gels and cures, providing greaterflexibility and cushioning in the cured seam, and also expanding toencase and bond with the backing 16 and backstitch fibers on theartificial turf.

In a preferred application, the two part polyurethane adhesive appliedto a flexible substrate material such as polyester fabric with athickness of approximately 0.015 inches will have a Shore A durometer ofless than 60, and in any event less than 70 or 90. Typical durometermeasurements for hot melt adhesives in cold weather may exceed 90.Durometer hardness is tested according to ASTM designation D 2240-05“Standard Test Method for Rubber Property—Durometer Hardness.” Othersubstrates may be suitable since the cured polyurethane providesadequate bonding strength without the requirement of reinforcing fibersfrom the substrate. Paper, woven fabrics, and nonwoven fabrics may allbe used to good advantage.

In addition, the seam may be tested according to the grab test, ASTM D5034 “Standard Test Method for Breaking Strength and Elongation ofTextile Fabrics”. Generally, grab tear strength measured according toASTM D 5034 for artificial turf must be at least 150 pounds and for someinstallations minimum requirements may be 200, 250, 300, or even 350pounds. The two part polyurethane system can achieve grab tear strengthsin excess of 400 or 450 pounds although a grab tear strength above 200pounds is likely be suitable for many applications, and 300 or 350pounds is readily obtained.

Turning then to FIG. 2, an exemplary polyurethane spray rig 50 isdepicted. The exemplary spray rig includes a generator, such as an 18KwH gasoline or diesel powered generator 56, a refrigerated air dryer53, an air compressor 51, a fresh air system with full face mask 57 forworkers and 200 foot breathing air hose. The polyurethane components maybe stored in drums 62 (part A polyol), 64 (part B isocyanate) and mixedin a reactor such as a Graco E20 52 or Graco E30 reactor and dispensedthrough a 200 foot heated hose 54 or extreme duty hose typically ratedover 3000 psi. Preferably the hose and spray gun will be rated for useover 5000 or over 6000 psi to allow for use with high solids andviscosity polyurethane mixtures. For use with the heated hose, a waterheater is also provided. A dispensing nozzle such as Graco' s XTR7 spraygun 55 is suitable for applying the mixed polyurethane components. Thespray gun allows the mixture to be deposited on the substrate at thedesired thickness, typically in the range of about 10 up to even 300mils as needed to bond well with the back side 16 of the artificialturf. The spray rig will also include ancillary items such as plumbingand electrical systems, spray hose rack, fresh air hose rack, filters,outlets, wall heater, tools, gloves, and other customary equipment.Suitable spray rig systems can be obtained from suppliers such as SprayFoam Systems under its ProPAK line of rigs.

The spray rig is mounted on wheels 60 and can be moved along the lengthof the artificial turf installation and the mixed polyurethane appliedto substrate across the 200 foot length of the hoses connecting thereactor to the polyurethane application gun. In this fashion, it isusually possible to lay two or three strips of artificial turf beforerelocating the spray rig.

For seaming smaller areas, such as for the insertion of white numeralson a green artificial turf surface, a portable spray rig may beemployed, such as the Graco XP70 plural component high pressure sprayershown in FIG. 4. When a smaller and more easily moved pressure sprayeris used, a shorter hose length is needed so the polyurethane mixture canbe deposited with less delay from the mix manifold to the spray head.

In FIG. 3, the process of applying the mixed polyurethane is illustratedwith the two strips of artificial turf, 10, 11 having first beenpositioned on the base material 18 so that the edges 20,21 to be seamedwere in close proximity. The first edge 20 on first artificial turfstrip 10 and the second edge 21 of the second artificial turf strip 11have been rolled back from one another leaving a space on the basematerial 18. The substrate 32 is then positioned on the base material 18along the seam location. The substrate 32 provides a consistent surfacefor the deposit of the seaming adhesive 30 which is preferably deliveredby a high pressure spray gun 55 connected by high pressure hose 59, orheated high pressure hose, from the mixing unit or reactor 52. Bycontrolling the temperature of the polyurethane components, andoptionally through the use of catalysts, appropriate working times forcomplex constructions, typically on the order of twenty to sixty minutescan be obtained in a wide range of temperature and humidity conditions.

It can be seen that the substrate 32 is wider than the layer ofpolyurethane material 30 so that it forms a barrier between thepolyurethane adhesive and the mounting surface. The width of thepolyurethane adhesive should be about three to eight inches so as toprovide a well distributed adhesive force. After the adhesive 30 hasbeen delivered, the rolled edges 20, 21 are again laid flat over theadhesive 30 and substrate 32 and the seam may be rolled with weight tofully enmesh the backing 16 of the artificial turf strips 10, 11 in theadhesive 30 before it cures.

FIG. 5 illustrates a top view of a sports playing surface 220 in theform of a football field. The surface is fabricated from a plurality ofstrips 222 of artificial turf placed lengthwise from one side 42 to theopposite side 43, shown as being laid top to bottom in FIG. 5. Theoverall length (W) of the field 220 extending from a left end 44 to aright end 45. In addition, a track 226 may be installed around theplaying surface 220. The playing surface 220 may have a series ofnumbers 231, letters 232, logos 234, yard lines 235, side line markings37, or other markings 239 including end zone markings 229 preferablyinlaid within the surface of one or more strips 222 of the artificialturf. An existing process of manufacturing these inlays is describedfurther below in connection with FIGS. 7-24. As shown in FIGS. 6Athrough 6C, inlays may be used for functional purposes such as soccerand American football field markings in FIG. 6A or midfield logos inFIGS. 6B and 6C.

The water jet cutting device 25 of FIG. 7 has a cutting bed 211positioned between side rails 212 and operated from controller 214. Thewater jet cutting system 25 utilizes belt drives 216,218 to move thewater jet 219 over the bed 211 as desired. The belt drive 216 moves thecross bar 215 in the direction of the X-axis from left to right whilethe belt drive 218 on the cross arm 215 moves the water jet head 219 upand down in the direction of the Y-axis.

In FIG. 8, the back surface 24 of a strip of artificial turf is visiblebetween the side rails 212 of a water jet cutting system 25. The crossarm 215 moves the cutting water jet head 219 laterally in theillustrated configuration while the cross arm 215 can be moved up anddown to provide complete freedom of position over the back 24 ofartificial turf. The controller 214 is utilized to cut desired shapes toform inlay segments from the artificial turf. In FIG. 9, it can be seenthat many inlay segments have been removed from the artificial turfdisclosing the bed 211 upon which the turf was resting.

FIG. 10 is an illustration of a work area for the assembly of an inlayin the form of a planar work surface 250 covered with plastic sheeting251. In FIG. 11, inlay segments 61,65,63 have been positioned on plasticsheeting 51. These inlay segments 61,65,63 are of a first color. In FIG.12, additional inlay segments 71,72,73 are of a second color and otherinlay segments 81 are of yet another color. The inlay segments arepositioned on the plastic sheeting 251 with their backing side facingupward and the surface of the artificial turf facing downward onto theplastic sheeting.

After inlay segments are positioned, there is a step of initiallyjoining the segments together as shown in FIG. 13. Workers positionthemselves adjacent to the edges of inlay pieces that are to be joinedtogether with hot melt guns 90, hot melt gun rests 91 and support pads92 for those tools. In addition, workers will utilize pressure boards 93and hand tools 94 as shown in FIG. 14 to create joining seams utilizinghot melt adhesive. Typical polyurethane reactive hot melt adhesives usedare Versatac, 1946, 400S and 900S, having viscosity of about 8000 cps.The worker positions the edges of adjacent inlay pieces in immediateproximity and applies the hot melt gun 90 to dispense flowable hot meltadhesive along seams 96. Once a segment of a joining seam has beenformed and set, the cooling blocks 93 are moved over the seam and weightis applied which cools and sets the seam and the worker positions anadditional portion of inlay segment edges and applies hot melt adhesiveto another segment of the seam. After all of the seams 96 have beenformed, the inlay 100 is in one piece. However, the hot melt adhesive isinadequate to hold the inlay segments securely so additional securing isrequired.

In FIG. 16, a substrate 84 coated with polyurethane adhesive on itsdownward facing side is being applied along the seams 96 shown in FIG.15. As shown in FIG. 17, the substrate 84 is laid out on a work surface79 and a mixed polyurethane adhesive 133 is poured on the substrate andspread with a doctor blade 86 to a relatively uniform coating. Then thesubstrate 84 is placed with the polyurethane adhesive face down on theseams 96 of the inlay and pressed into the carpet backing along theseams as shown in FIG. 18A. In lieu of manually preparing adhesivecoated strips, polyurethane reactive hot-melt, referred to as “blueglue” (HMPUR12-2010 BLUE), HMPUR12-3000 and HMPUR12-3000 SUMMER) may beemployed. The blue glue is sprayed directly on the hot melt seams asshown in FIG. 18B by a glue machine that heats and dispenses atrelatively low pressure, a width of glue adequate to cover the seamswithout manual spreading or application of substrates.

Eventually, all of the seams 96 of the inlay 100 are covered with thepolyurethane adhesive coated substrate strips 84 as shown in FIG. 19 andthen a top plastic sheeting 252 is placed over the inlay and the inlayis smoothed with rollers 253 as shown in FIG. 20. When this process iscompleted, plywood boards 254 are placed on top of the inlay overnight,and preferably for about twenty-four hours, so that the polyurethaneadhesive can cure as shown in FIG. 21. Once the curing is relativelycomplete, the plywood 254 is removed and the top plastic sheet 252 isremoved and the inlay can then be manipulated as shown in FIG. 22. Whenthe inlay is placed with the face side up, the graphic appearance of theinlay is obvious as shown in FIG. 23 and the final finishing to ensureuniformity of seams and fibers adjacent to the seams takes place asshown in FIG. 24.

Referring now to FIGS. 25A and 25B, the prior art joinder of two inlaysegments 120,121 is shown. Inlay segments 120,121 each includeupstanding filament material 122 resembling or simulating blades ofgrass extending upwards (or downward when positioned for inlay joinder)from a woven backing 124. After the filament material 122 has beentufted in the backing 124, a secondary backing 126 is applied. Thisbacking may be a single layer of resin such as urethane or latex, and itmay also include a cushion layer.

The first inlay segment 120 has a first edge 130 and the second inlaysegment 121 has a second edge 131 and the edges 130,131 are seamed inclose proximity to one another by the placement of a bead of hot meltadhesive 132, such as Versatac, a polypropylene based hot melt system.Over the hot melt is placed the substrate 84 with the doctored layer ofpolyurethane adhesive 133. Over time the hot melt adhesive 132deteriorates as shown in FIG. 25B. Segments of the hot melt adhesive maybecome brittle and break away entirely or simply crack and leave onlyfragments of the hot melt bead 132 in place. This causes the edges130,131 to be at least partially exposed to contact upon the surface ofthe artificial turf and also permits moisture to enter the artificialturf along the seam and attack the adhesion between the polyurethane andthe secondary backing 126.

To address this concern, the use of a hot melt bead 132 can be avoided.In FIG. 26A, a scrim mesh segment 110 and a scrim mesh roll 111 aredisclosed. In each case, there is a mesh material, typically of afiberglass textile, in a plain weave with weft and warp oriented strandsof filaments, and with the mesh openings providing direct access to atleast 50% of the backing surface upon which it is applied due to thesize of the mesh grid relative to the fiberglass textile filaments. Anexemplary fiberglass textile would be composed principally of fiberglassfilaments, polyester filaments, and polymeric coatings and adhesives. Atypical mesh will have strands less than 1/25^(th) inch and typicallyabout 1/30^(th) to 1/40^(th) inch in diameter and a pick count of 4 to 8strands per inch in both the vertical and horizontal directions. Such atextile provides direct access to about 66% to 90% of the backingcovered by the scrim.

Along each longitudinal edge of the mesh grid 115, is pressure sensitiveadhesive 112,114. Each longitudinal line of pressure sensitive adhesivemay be about one-half inch in width and one-eighth inch in thickness.After application to the backing, peel away tack strength according tothe PTSC procedure are preferably in excess of 30 oz./inch or loop tackstrength in excess of about 2.5 lb/in². A peel-away front sheet 117 andback sheet 116 is applied to protect the pressure sensitive adhesivefrom engaging contact before use. In use, the front sheet 117 of asegment of the mesh scrim 110,111 is removed and the scrim applied alonga seam line 96 of the inlay 100 as shown in FIG. 27. The scrim meshrolls 111 can be cut to length for longer seam segments while the scrimmesh segments 110 can be applied rapidly without cutting and areparticularly useful along curved seams 96. Once the mesh scrim isapplied, the backing sheets 116 may all be removed. Front sheets 117 andbacking sheets 116 may be colored or imprinted with directions forclarity of use, particularly if the pressure sensitive adhesive isoriented for best adhesion in one direction. Once the mesh scrim iscompletely in place and backing sheets removed, a two part curingpolyurethane system such as UL4500A and UL4500B is mixed and appliedusing an applicator such as a Graco XP70. Alternatively, a two-partpolyurea system may be used, typically with shorter gel and curingtimes, such as VERSAFLEX low pressure products, with a curing time often to twenty minutes. The application may be performed directly on thescrim and focused in between the pressure sensitive adhesive sections,though no serious degradation to overall seam strength occurs bycovering the pressure sensitive adhesive. The depth of application isbetween about 0.05 to 0.25 inches, and preferably about 0.1 inches.

Because the scrim mesh is generally between about 3-10 inches in width,there is usually over 2 inches of polyurethane or polyurea and scrim oneither side of the seam line interior of the line of pressure sensitiveadhesive. Accordingly, even if the pressure sensitive adhesive shoulddegrade, an adequate bond exists between the polyurethane or polyureaand mesh scrim and secondary backing. Furthermore, the polyurethane orpolyurea is mixed to an appropriate viscosity and applied so that itwill flow into the seam gap between the first edge 130 and second edge131 much as the hot melt bead does in the initial bonding of the presentseaming process. The depth of application of the polyurethane orpolyurea is preferably sufficient to cover the scrim so that it isencapsulated or nearly encapsulated and thereby provides the additionalstability of the fiberglass textile to the seam.

In FIG. 26B, a scrim mesh segment 110 is shown with mesh grid 115,pressure sensitive adhesive 112,114 along each longitudinal edge,peel-away front sheet 117 and back sheet 116 just as in FIG. 26A.However, a central adhesive strip 118 has been added, together withcenter marker 119. The central adhesive strip is preferably about 0.5 to1.0 inches wide and about one-eighth inch in thickness. The centermarker may be a contrasting color thread or yarn, or may be colored onor in the central pressure sensitive adhesive strip. The center markerfacilitates alignment of the mesh segment 110 directly over the seam gapbetween the first edge 130 and second edge 131. With the scrimconstruction of FIG. 26B, the seam gap is not filled by polyurethane orpolyurea adhesive, and instead the pressure sensitive adhesive holds theedges in place. Still, it will be seen that the mesh provides directaccess to over two-thirds of the backing area not blocked by pressuresensitive adhesive strips, and that at least one longitudinal row ofpicks, and preferably two or more, are located exterior of the pressuresensitive adhesive strips 112,114 along each longitudinal edge, andbetween the central strip 118 and the side strips 112, 114. In thisfashion, there is at least about a quarter inch of mesh where thepolyurethane or polyurea adhesive may form a good bond to the secondarybacking 126, both at the edges and on either side of the center adhesivestrip 118. Mesh segments 110 are preferably between about 5 to 12 inchesin length so that they can be placed with substantial accuracy abovecurving seams. The central adhesive strip 118 should always bridge theseam between edges 130, 131. Instead of a solid strip of pressuresensitive adhesive, the PSA can be applied only to the strands formingthe mesh. This allows greater pass through area for the polyurethane orpolyurea adhesive, but makes it more difficult to obtain the desiredpeel away strength.

In FIG. 28, the first inlay segment 120 and second inlay segment 121 areillustrated with the scrim 110 applied where the fiberglass textile mesh115 can be seen in the sectional view encased in a pressure sensitiveadhesive 112,114 and polyurethane 138. Polyurethane has flowed in thegap between edges 130 and 131 and has bonded to the secondary backing126. In this fashion, even if the pressure sensitive adhesive 112,114degrades, there is no weakening of the seam between edges 130 and 131.

FIG. 29 illustrates the steps involved in the fabrication of an inlayaccording to an embodiment of the invention.

Numerous alterations of the structure and techniques herein disclosedwill suggest themselves to those skilled in the art. However, it is tobe understood that the present disclosure relates to the preferredembodiment of the invention which is for purposes of illustration onlyand not to be construed as a limitation of the invention. All suchmodifications which do not depart from the spirit of the invention areintended to be included within the scope of the appended claims.

I claim:
 1. A mesh of fiberglass textile having weft and warp orientedstrands of filaments less than 1/25^(th) inch in diameter and a pickcount of between four and eight, wherein the face of the mesh haspressure sensitive adhesive applied along the longitudinal edges of themesh, spaced inward from the longitudinal edges by at least 0.25 inches,the pressure sensitive adhesive having a width of about 0.25 to 0.5inches and a thickness of about 0.125 inches, and a peel away frontsheet covering the pressure sensitive adhesive before use.
 2. The meshof claim 1 further comprising a central pressure sensitive adhesivestrip.
 3. The mesh of claim 2 further comprising a center marker in thecentral pressure sensitive adhesive strip.
 4. The mesh of claim 3wherein the center marker is a colored yarn.
 5. The mesh of claim 1having a peel away tack strength of at least 30 ounces per inch.
 6. Themesh of claim 1 provided in a roll.
 7. The mesh of claim 1 provided in asegment between 5 and 12 inches in length.
 8. The mesh of claim 1provided in a width of between 3 and 10 inches.
 9. The mesh of claim 2wherein the central pressure sensitive adhesive strip has a width ofbetween 0.5 and 1.0 inches and a thickness of about 0.125 inches. 10.The mesh of claim 1 used to join first and second sections of artificialturf.
 11. An inlay comprising a first artificial turf segment having afirst curved edge contour and a second artificial turf segment having asecond curved edge contour that matches the first edge contour and ispositioned proximate thereto, each artificial turf segment having a topsurface with upstanding filament material and an opposite bottomsurface, an open mesh scrim having a pressure sensitive adhesive alongits left edge attaching the scrim to the bottom surface of the firstartificial turf segment and a pressure sensitive adhesive along itsright edge attaching the scrim to the bottom surface of the secondartificial turf segment, and a pressure sensitive adhesive along thecenter of the scrim joining the first and second edges.
 12. The inlay ofclaim 11 wherein the scrim has a width of between about 3 to 10 inchesand is woven with weft and warp oriented strands with between about 4and 8 picks per inch.
 13. The inlay of claim 11 wherein the scrim is afiberglass textile.
 14. The inlay of claim 11 wherein the polyurethaneor polyurea encasing a central portion of the scrim has a thickness ofless than 0.25 inches.
 15. The inlay of claim 11 wherein thepolyurethane or polyurea encasing a central portion of the scrim has ahardness of less than 70 durometer.
 16. The inlay of claim 11 whereinthe pressure sensitive adhesive along the center of the scrim has acenter marker.